Now the groups these users belong to should also be sourced from crowd rather than ldap
Admin -> User groups
show groups that existed before the change to crowd as being sync'd from ldap.

How can they be changed so that they sync from crowd?

Will this work?
$ psql rhodecode
rhodecode => UPDATE users_groups SET user_group_description = 'Automatically created from plugin:crowd' WHERE user_group_description = 'Automatically created from plugin:ldap';

Is there any other condideration that should be addressed with this ldap to crowd change?